ALMATY, Oct 1 (Reuters) - Kazakh President NursultanNazarbayev sacked the head of the central bank on Tuesday andreplaced him with Deputy Prime Minister Kairat Kelimbetov, amove that could herald changes in the management of pension fundassets.

The presidential press service said monetary policy wouldremain unchanged.

Outgoing Grigory Marchenko, 53, had been at the helm of thecentral bank since 2009 and was largely responsible forreshaping the banking and pension systems in Central Asia'slargest economy.

Nazarbayev, a 73-year-old former steelworker who has ruledthe oil-rich state of 17 million for more than two decades, inJanuary ordered the assets of 10 Kazakh private pension funds tobe corralled into a state fund called GNPF.

As new central bank head, Kelimbetov will be responsible formanaging the assets of the single fund.

"It would have been a better decision not to let Marchenkogo and instead appoint him to manage the assets of this singlepension fund - to be responsible for the decisions for which hehimself had lobbied," said analyst Aidos Sarym.

Marchenko and Kelimbetov, 44, have differed more than onceon the way Kazakhstan's reforms should develop.

Shortly after quitting as deputy prime minister in 2004,Marchenko blasted Kelimbetov - then economy minister - over whathe called "fake calculations" for the state housing programme.Kelimbetov, in turn, accused him of being too emotional.

After the merger of pension funds the bank would manage atotal of some $120 billion, including $23 billion in pensionfund assets. This represents 60 percent of the country's grossdomestic product, which stood at $200 billion in 2012, Marchenkosaid in an interview with Reuters last month.

Despite Nazarbayev assuring of the continuity of the centralbank's policy, some analysts said their could be some drasticchanges under Kelimbetov.

"Most probably, the process of regulating the single pensionfund will change. The pension fund will be more oriented towardsinvestment in infrastructure projects," said Sabit Khakimzhanov,chief analyst at Halyk Finance.

"One cannot exclude that the assets of the National Fundwill also be partly invested in infrastructure projects."

The National Fund, collecting windfall oil revenues andworth $66 billion, is now 100 percent invested abroad. Marchenkodid not rule out that with time some of it could be invested inpaying projects in Kazakhstan, subject to rigid expertise.

He told Reuters that he opted for 20 percent of the singlestate pension fund's assets to be invested abroad in 3 to 5years, boosting this share from today's 10 percent.

The government was charged by Nazarbayev with completingpension reform by the end of this year, but Marchenko toldReuters that it was not certain that this deadline would be met.

In 2011, Marchenko was a candidate for the top job at theInternational Monetary Fund.

"I would not be surprised if tomorrow he turns up at aRussian bank or an international structure," said analyst Sarym.

Kelimbetov graduated from Moscow State University andGeorgetown University in the United States. One of his recentposts was that of economy and budget planning minister.

"I believe that his knowledge of the country's economy andfinancial situation will have a positive impact on the work ofthe National Bank," Nazarbayev said.